| For genetic improvement of plant, mutation breeding is one of the important means. In order to meet the demand for numerous varieties of tea breeds resulting from the development of Camellia oleifera industry,Jiangxi academy of forestry attempt to innovate Camellia breeding material by mutation breeding technology, aiming to cultivate high-yield and high quality Camellia oleifera of new varieties and achieve new breakthroughs in the study of Camellia oleifera.In this study, Camellia oleifera breeding material mutated by Co60 gamma ray radiation and “the Shen zhou eight” is taken as subject of the research. Through the field test, we observed phenotypic traits and measured the photosynthetic physiological characteristics of Camellia oleifera after mutated, and conducted a comprehensive analysis of the effects of mutagenesis on photosynthetic characteristics and the growth of Camellia oleifera, Results show that:(1)A certain degree of regularity can be recorded in terms of the effecs of Co60 gamma ray radiation on phenotypic traits of Camellia oleifera specific performances are recorded as follows:the significant inhibition effect on seeding height and ground diameter growth has been found after Co60 gamma ray radiation.The effect of autumn shoots and branch number has not reached a significant level,however,no obvious deformity in leaves has been found.(2)The effect of space mutation on phenotypic traits of Camellia oleifera shows the space mutation not only can promote seedling height and ground diameter growth,but also can increase the lengths of summer and autumn shoots observably, yet fail to influence leaf morphological characters and.(3)The results of the study of the influence of Co60 gamma ray radiation on Photosynthetic Characteristics of Camellia oleifera are as follows: the photosynthetic capacity of Camellia oleifera has been enhanced after Co60 gamma ray radiation in the spring shooting stage, growth development stage and dormancy stage.compared with the reference group, the light compensation point(49.69 umol.m-2.s-1) has risen, significantly, whereas the light saturation point(20.75 umol.m-2.s-1) has dramatically dropped, and the maximum net photosynthetic rate has decreased as well,So that mutation reduces the adaptability of Camellia oleifera seedlings to light environment and weaken the photosynthetic potential.The chlorophyll content of radiated seedlings were all increased, indicating that Co60 gamma ray radiation treatment can promote the photosynthetic capacity, but the effect was not significant. The order of seasonal variation of photosynthetic rate with Camellia oleifera at different stages was spring shooting stage>growth development stage>dormancy stage. In the spring shooting stage and the growth development stage, net photosynthetic rate was increased, showing that,in general, the Co60 gamma ray radiation treatment can improve the photosynthetic capacity of Camellia oleifera.(4) The net photosynthetic rate of seedlings in the spring shooting stage and growth development stage are the same as that of the check, but the photosynthesis during the dormancy stage is significantly promoted.The light compensation point( 29.64 umol.m-2.s-1) has risen, significantly, whereas the light saturation point(10 umol.m-2.s-1)has dramatically dropped, but the light saturation point has decreased 11.24 umol.m-2.s-1, indicating that space mutation improves the ability of Camellia oleifera with light.All the chlorophyll contents were higher than the control, showing that the space mutation treatment can increase the content of chlorophyll in plants and improve the photosynthetic capacity of Camellia oleifera.The sequence of seasonal variation of photosynthetic rates of Camellia oleifera at different stages was as follows: growth development stage>spring shooting stage>dormancy stage. In the three stage, net photosynthetic rate was significantly higher than ck, showing that the space mutation has improved the photosynthetic capacity of Camellia oleifera. |
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